Compound positioning apparatus for hospital beds and the like



L. E. HOLM Oct. 18,1966

COMPOUND POSITIONING APPARATUS FOR HOSPITAL BEDS AND THE LIKE '5 SheetsSheet 1 Filed Aug. 17, 1962 i n .1 II

INVENTOR.

LUTHER E. HOLM I9 ATTORNEY L. E. HOLM COMPOUND POSI TIONING APPARATUS FOR HOSPITAL BEDS AND THE LIKE Filed Aug. 17, 1962 '5 Sheets-Sheet 2 6 mm mm mm B Em I u I I I A m o; d I! A 8 mm 8 m mm q Q mm mm wm Illa-Illlul-I I we L WOC LUTHER ATTORNEY L. E. HOLM Oct. 18, 1966 COMPOUND POSITIONING APPARATUS FOR HOSPITAL BEDS AND THE LIKE 5 Sheets$heet 3 Filed Aug. 17, 1962 INVENTOR. LUTHER E. HOLM 2i Aw;

ATTORN EY Oct. 18, 1966 L. E. HOLM 3,

COMPOUND POSITIONING APPARATUS FOR HOSPITAL BEDS AND THE LIKE Filed Aug. 17, 1962 '5 Sheets-Sheet 4 v 73 7' 8O 82 l I INVENTOR. v LUTHER E. HOLM gm G. M

AT TORN EY L. E. HOLM Oct. 18, 1966 COMPOUND POSITIONING APPARATUS FOR HOSPITAL BEDS AND THE LIKE 5 Sheets-Sheet 5 Filed Aug. 17, 1962 FIG.|2

INVENTOR. LUTHER E. HOLM BY 9 ATTORNEY United States Patent COMPOUND POSITIONING APPARATUS FOR HOSPITAL BEDS AND THE LIKE Luther E. Holm, Kenosha, Wis., assignor to Holms Manufacturing Co., Kenosha, Wis., a corporation of Wisconsin Filed Aug. 17, 1962, Ser. No. 217,707

17 Claims. (Cl. 68)

This invention relates to hospital beds and more particularly to compound positioning apparatus for hospital beds and the like, although it and certain features thereof may be employed with equal advantage for other purposes.

It contemplates more especially the provision of power operated instrumentalities for general purpose hospital beds having springs which can be readily manipulated into any of the various available positions which are required at one time or another for the treatment of patients in all of the specialties. This includes the back and knee rest positions, the Trendelburg position, the reverse Trendelburg position, and the control of these positions at any point between the extreme limits of adjustment of the bed springs.

Many types of bed spring operators have heretofore been provided for hospital beds and hospital bed springs, but these either are too expensive in construction or do not provide the margin of safety required in hospitals to insure against slippage, full release upon failure of any part or element or through abuse in use or operation of the controls. It should be borne in mind that power adjusted beds are manipulated by the nurses, the doctors, and the patients themselves so that it becomes a matter of serious concern when the bed is electrically or power operated to assume all positions, that all inoperative elements are locked for safety.

With the teachings of the present invention, the power action is primarily mechanical rather than electrical, eX- cept that the latter is the propelling action for the mechanical drives that manipulate the bed spring levers and control the limit of movement. Further, the mechanical elements are either in moving or braking position and the latter governs until operative full driving connection is effected to insure against slippage and full release of the bed spring parts under any circumstances regardless of motor failure, power failure, or the failure of any part or element of the positioning apparatus. When in driving position, the mechanism including the bed spring and the patient thereon, is or are held in position by the applied power, the gears, and the levers connected to the positioning apparatus. Spring applied brakes hold the positioning apparatus for both the head and knee rests so that when one or the other are in operation, the power engagement releases the brake against the action of springs to insure that all parts not in operation are locked and braked without any possible human error.

One object of the present invention is to simplify the construction and improve the operation of devicesof the character mentioned.

Another object is to provide improved mechanical drives for the head and knee rests of hospital bed springs so that either may be operated by a single electric motor which provides the propelling source therefor while the drives insure safe actuation within the desired limits of movement and positive locking during inoperation for adjusting the bed spring.

Still another object is to provide an improved driving and braking mechanism for both the head and knee rest portions of bed springs so that one or the other may be actuated by a single motor and positively locked during inoperation without any possible human or mechanical failure.

A further object is to provide shiftable mechanical control means and braking means for plural operators to render such responsive to a single power source with automatic braking action to hold the elements in locking position against slippage or failure in holding bed spring parts in their adjusted position.

A still further object is to provide a novel combination of clutching and de-clutching elements on plural drive mechanisms for beds so that one or the other are operative to displace and lock parts in their adjusted positions.

Still a further object is to provide improved and simplified plural drives in mechanical movements with aligned clutching and declutching elements effective for operating and locking parts to adjusted positions.

Other objects and advantages will appear from the following description of an illustrated embodiment of the present invention.

In the drawings:

FIGURE 1 is a front view in elevation of a hospital bed spring power actuating mechanism embodying teachings of the present invention, the head and knee rest portions of the bed spring shown in elevated position.

FIGURE 2 is an enlarged front view in elevation of the knee rest portion of the bed spring and the plural drives for both head and knee rests shown in FIGURE 1.

FIGURE 3 is an enlarged plan view of the electric motor drive for the plural power shafts comprising part of the head and knee rest adjusting instrumentalities.

FIGURE 4 is a fragmentary sectional view of the knee rest drive taken substantially along line IVIV of FIG- URE 3.

FIGURE 5 is a fragmentary sectional view in elevation of the head rest drive taken substantially along line V-V of FIGURE 3.

FIGURE 6 is an enlarged plan view of the plural drive mechanism shown in FIGURE 3 with the aligned clutching and declutching elements for the plural drives being shown in section for clarity of illustration.

FIGURE 7 is a fragmentary end view in elevation of the plural drive mechanism and shift lever for clutching and declutching the drives alternately viewed substantially from line VII-VII of FIGURE 2.

FIGURE 8 is an enlarged sectional plan view of the plural drive transmission taken substantially along line VIII-VIII of FIGURE 7 with the shift lever pins and transmission parts ina shifted position for operating the head rest of a bed spring.

FIGURE 9 is a view similar to FIGURE 8 with the shift lever and transmission parts in alternate position for operating the knee rest of the bed spring.

FIGURE 10 is a plan view of the shift lever and connected links for the plural drive transmission illustrated in FIGURES 8 and 9.

FIGURE 11 is a fragmentary front view in elevation of the shift lever and connecting links illustrated in FIGURE 10, it being shown in neutral position with both brakes in locking position and neither drive shaft connected to the motor.

FIGURE 12 is a view of the shift lever shown in FIGURE 11, but with the shift lever positioned as shown in FIGURES 2 and 9 for operating the knee rest.

FIGURE 13 is a perspective view of a free wheeling driver that fits onto the ends of both feed screws illustrated in FIGURES 4 and 5.

The structure selected for illustration is not intended to serve as a limitation upon the scope or teachings of the invention, but is merely illustrative thereof, and there may be considerable variations and adaptations of all or part of the teachings thereof depending upon the dictates of commercial practice. The present invention comprises in its environmental structure a bed spring frame 10 to which upstandings bracket plates 11 are attached substantially intermediate the ends thereof to support the sections of a hospital bed spring 12 which usually includes a head rest portion 13 pivotally connected at its lowermost ends thereof to the bracket plates 11 as at 14. This section 13 usually supports the head and entire thorax of a patient. The bed spring knee rest portion 12 usually consists of two inter-pivoted spring sections 15-16 movably joined at 17 to support the lower extremities and torso of the patient. The head rest section 13 actually serves as a back rest as well so that for purposes of this disclosure and for brevity it shall be termed a head rest while the sections 15-16 which are pivotally adjustable relative to each other is usually termed collectively as a knee rest. The knee rest 15-16 is pivotally connected at the extreme. upper ends of the section side rails of section 15 to the bracket plate 11 as at 18 to serve as either a rigid flat spring 13-15-16 in a common plane or to assume a large variety of angular positions relative to each section thereof so that doctors and nurses may treat a large number of different ailments and afilictions as well as to position the patient in any number of different appendage relationships for utmost comfort to the patient depending upon the afflictions and the experience of each patient. This may vary from time-to-time during short or long intervals of rest so that the patient as well as the attendants should be in a position to control the bed spring contours.

As shown, the foot section 16 of the bed spring 12 is usually fitted with angular adjusting instrumentalities to manually and initially position the knee-rest sections 15- 16 relative to each other, This is accomplished through bed frame supporting arms or rails 19 connected to the pivot 17 on each side of the bed spring 12 with the extreme lower or footends thereof fitted with roller brackets 20, that ride on the side rails of the bed frame 10. The angular supporting rails 19 terminate in downward extremities 21 (FIGURES 1 and 2) that fit inside the horizontal rails of the bed frame 10 to guide the traverse of the roller brackets 20 on and along the top flange of the bed frame rails 10. The foot section 16 has depending levers 22 pivoted to the side rails thereof as at 23 and carry lateral pins 24 at their other ends to register with one of a series of complemental slots 25 provided in the upper edges of the supporting arms or rails 19. With this arrangement, a much wider range of manual and initial adjustment of angularity is provided along with the power pivotal operation of the section 15 which also affects the angularity of the section 16 therewith as will appear more fully hereinafter.

The head rest spring section 13 is pivotally connected to the bed frame 10 through links 26-27 that are pivotal- 1y connected at their ends by means of pins 28, and these links 26-27 in turn are pivotally connected to the head rest 13 and frame rails 10 on each side of the bed as at 29 and 30, respectively. The link 27 is attached at its lower end to a crank arm 31 that operates relative to the pin or trunnion 30 to impart corresponding oscillatory motion to the lever 27 to raise and lower the head rest spring section 13 responsive to the operation of the power feed to be hereinafter described. Similarly, the knee rest spring sections 15-16 are pivot-ally supported by the bed spring frame 10 through a pair of links 32 pivoted at their upper ends to the knee rest section 15 as at 33. The other ends of the links 32 are pivoted as at 34 to a shorter lever 35 that is pivotally supported by a pin or trunnion 36 anchored in the side rails of the bed frame 10. A crank arm lever 37 is attached to the link 35 to impart oscillatory movement to the links 32-35 to raise and lower the knee rest spring sections 15-16 and change the angularity thereof responsive to the operation of the power feed to be hereinafter described.

As shown, the crank arms 31 and 37 actually comprise spaced plates (FIGURES 4 and which receive tubular screw feed telescopic housings 38-39 therebetween for pivotal connection to the forward ends thereof by means of pins 40-41 extending therethrough to maintain the parts in assembled relation and serve as a pivotal connection therebetween. Ball bearing screw nuts 42-43 (FIGURES 4 and 5) are anchored in the other ends of the elongated telescopic tubular housings 38-39 to mesh with power feed screws 44-45 that are confined within the tubular.

units 48-49 (FIGURES 4, 5 and l3) having cross-pins 48-49 proximate to their free ends of the screws 44-45 to ride over confronting pin declutching end teeth on the screw nuts 42-43 to provide a declutching movement. These end teeth are pitched in the direction to permit the end screw pins 48'-49 to ride thereover so that the screw nuts 42-43 will turn with the screws 44-45 so that relative movement therebetween is arrested and no further displacement between the telescopic tubes 38-46 and 39- 47 is possible. The drive units 48-49 involving this free wheeling action are of standard construction which permit the screws engaging the screw nuts 42-43 to idle at the end of their extreme movement of rotation and displacement along the screws 44-45 to provide a free-wheeling drive effect to avoid injury to the cooperating power feed parts of the plural drives as the electric motor continues to operate responsive/to a manual button switch control should the operator fail to release the button switch at the end of the maximum travel of the screw feed ball bearing nuts 42-43 depending upon which of the two is in gear as will appear more fully hereinafter.

The screw feeds or feed screws 44-45 are anchored at their rearward ends to cylindrical heads 50-51 having axial bores 52-53 therein for the reception of the feed screw extremities 54-55, and pins 56-57 extend diametrically therethrough to connect the feed screw ends 54- 55, the cylindrical heads 50-51, and the sleeve tubes 46-47 together for operation in unison as part of the plural drives 38-44-46 and 39-45-47 that respond to the electric motor alternately or selectively depending upon the transmission shift setting to be described hereinafter. It should be noted that the drive 38-44-46 in operation of the bed spring head section 13, changes its axial position in a vertical plane and to accommodate this movement the electric drive motor is pivotally mounted on the frame 10 as illustrated (FIGURE 6) and will appear more fully hereinafter. Due to the inclination and limited vertical displacement of the drive 39-45-47 in operation, the cylindrical connector head 51 is part of a universal joint 58 having a cross-pin 59 as a pivotal connector therefor (FIGURE 5). A rubber or other flexible sleeve 60 envelops the universal joint 58, and it constitutes an extension of the external drive sleeve 47. The cylindrical heads 50-51 for the feed screws 44-45, connect to a manual shift transmission 61 (FIGURES 4, 5, 6, 8 and 9) to control either feed screw 44-45 for selective connection to the power source, in this instance an electric motor. It should be noted, however, that the feed screw connector head 51 establishes its operative connection with the transmission 61 through the universal joint 58 owing to the inclination of the power drive 39-45-47; however this is a matter of design and arrangement of parts rath than a requirement.

The manual controlled transmission comprises, in this instance, a substantially rectangular casing 61 having spaced bearing bosses 62-63 formed in the end wall thereof which confronts the screw feed connector heads 50 and the universal joint 58, to provide axially aligned bearings 64-65 that rotatively support stub shafts 66-67 having external stop collars 68-69 and internal braking elements 70-71. End thrust ball bearing raceways 72-73 are provided between the casing end Wall and the tubular braking elements 70-71 which have one sleeve part thereof secured to the stub shafts 66-67 to rotate therewith while a toothed peripheral stationary sleeve 74 and 75 is disposed over each of the rotary portions of the braking elements 70-71. The toothed peripheral stationary braking elements 74-75 are held stationary by means of laterally extending lugs 76-77 (FIGURES 8 and 9) which register with and abut against a stud collar 78 anchored in the end wall of the transmission casing 61 between the external bearing bosses 62-63 thereof. Compression springs 78-80 envelop the reduced sleeve portions of the peripherally toothed braking elements 74-75 to normally urge the latter rearwardly (toward the right in FIGURES 8 and 9) while held against rotation by the lateral lugs 76-77 thereon which permit linear displacement thereof along the rotary sleeve mounts 70-71 constituting part of the braking elements 74-75.

Complemental to and confronting the stationary braking element toothed peripheral surfaces 74-75, are similarly sized and shaped toothed peripheral surface members 81-82 having reduced tubular shank portions 83-84 defining peripheral shoulders 85-86 serving as the abutments against which the transmission shift lever pins react as will be described infra. The tubular shanks 83-84 are diametrically slotted as at 87 to receive pins 88, in this instance two, which are anchored in the stub shafts 66- 67 to rotate the toothed braking elements 81-82 while permitting their linear displacement along the shafts 66- 67 in one direction responsive to the urge of compression springs 89-90 which envelop the stub shafts 66-67 internally of the opposite braking element mounts 70-71. The braking element complements 81-82 are displaced linearly along the stub shafts 66-67 in the direction opposite to the urge of the springs 89-90 by a shift lever 91 that is horizontally disposed through the side wall of the transmission casing 61 to present depending pins 92- 93 (FIGURE 7) in the path of the peripheral shoulders 85-86 to displace either braking element complement 81 or 82 against the urge of their respective springs 89-90 responsive to pivotally shifting the lever 91 about its pivotal mounting pin 94 depending therefrom intermediate the shifting pins 92-93.' The pivotal mounting pin 94 for the shift lever 91, fits into a bearing sleeve 95 extending vertically upward from the transmission casing 61. The manual shift lever 91 is retained in position with its intermediate depending pin 94 with the upstanding hearing sleeve 95, by the transmission casing cover 96 (FIG- URE 3) which is secured thereto in any suitable manner.

As shown, the braking element sleeves 83-84 terminate at their free ends in clutching teeth 97-98, respectively, disposed around the edge periphery thereof in complemental alignment with clutching elements 99-100 journalled on stub shafts 101-102 having sleeve bearings 103-104 disposed therebetween for substantially free rotation of the clutching elements 99-100 thereon. The clutching elements 99-100 have complemental peripheral edge teeth 105-106 thereon in confronting end-to-end relation with the counterparts 83-84 whose clutching and declutching teeth 97-98 cooperate therewith to rotate one or the other of the stub shafts 66-67 for operating their corresponding feed screws 44-45 which translate the ball bearing drive nuts 42 or 43 in extending or telescoping the tubular sleeves 38-46 or 39-47 to actuate the linkage 26-27 or 32-35 to raise or lower the head rest 13 or knee rest 15-16 depending upon the position of the manual shift lever 91 and the direction of rotation of an electric motor 107. The electric motor 107 is of the reversible type which is pivotally supported between a bracket mount 108 (FIGURE 3) and a cross bar 109 which, in turn, are supported by cross member channels 110-111 that extend between and are anchored to the side rails of the bed frame however, the electric motor bracket mount 108 is pivotally attached directly to the front side rail of the frame 10 to support the electric motor 107 in an offset position but in the plane of the transmission casing 61 so that the standard reduction gearing built into the motor 107 will present a driven armature shaft 112 between the stub shafts 101-102. The driven motor shaft 112 is journalled in a bearing 113 (FIGURES 8 and 9) carried by the transmission casing end wall between and horizontally aligned with the stub shafts 101-102; however, as the drive 38-44-46 changes its axial position in a vertical plane as the electric motor 107 operates the head rest section 13 therewith, the electric motor 107 will slightly turn on its pivotal mount between the supporting brackets 108-109 to accommodate the movement of the drive 38-44-46 without requiring a universal joint.

The armature driven shaft 112 has a spur gear 114 fixed thereto for rotation therewith inside the end wall of the transmission casing 61 to mesh with corresponding sized and complemental spur gears 115-116 formed integral with the clutching elements 99-100 for driving rotation of either and both in opposite directions continuously and at the same speed so long as the electric motor 107 is energized. The electric motor 107 is controlled by a two position switch 117 (FIGURE 2) that extends from an.

electric cord 118 leading to the electric motor 107 (FIG- URE 3) to control the operation thereof and the direction of rotation by finger flipping the switch 117 to one of two directional positions. The switch 117 is within the grasp of the attendant or the patient for exercising the desired control thereof to accomplish the power actuation of the head rest 13 or the knee rest 15-16 up or down selectively depending upon the position of the switch button 119 and the position of the transmission shift lever 91.

The manual shift lever 91 for controlling the transmission selection of motor driven rotation for the screw 44 or screw 45 that drive the ball bearing nut drivers 42 or 43, respectively, to displace the telescopic tubes 38 or 39, is remotely controlled and shifted within convenient reach of the attendants and also the patient in bed confinement, To this end, the shift lever 91 has a universal joint 119 fitted to the extremity thereof for connection to an elongated rod 120 (FIGURES 10 to 12) which has a substantially elongated rectangular plate 121 anchored to the extremity thereof proximate to the control support bracket plate 11. The elongated rod extension plate 121 has a stud 122 anchored therein to register with a substantially arrow-like shaped slot 123 provided in a handle lever 124 which is pivoted to the front side rail of the bed frame as at 125. The plate anchored pin or stud 122 has a fastener head such as a nut 126 threaded thereto to confine the stud 122 in the slot 123 against accidental removal.

The other end of the rod extension plate 121 has a short substantially U-shaped horizontally disposed slot 127 provided therein to cooperate with a stud 128 which may register with either offset end notch 129-130 at or between the ends of the slot 127 depending upon the position of the hand shift control lever 124 in any one of three positions defined by the ends of the arrow-shaped slot 123 for the shift to either the head rest operating screw 44 or the knee rest operating screw 45 controlled by the clutching elements 83-99 or the clutching elements 84-100 being in operative engagement. The clutching and declutching of the complemental clutch elements 83-99 and 84-100 is effected by pivotally displacing the handle lever 124 to the extreme forward and rearward positions limited by the slot 123 in engagement with the stud 122, and these positions are indicated by the indicia Head and Foot on the bracket plate 11 with the arrows pointing in the direction of required movement of handle lever displacement (FIGURES 1 and 2). It should be noted that the mid high point of the slot 123 determines the neutral position of both clutching elements 83-99 and 84-100 which is the illustrated position of FIGURE 11 during which time the stud 128 is positioned between the extreme vertically offset slots 129-130 at which point both braking elements 74-81 and 75-86 are in operative engagement with the clutching elements 83- 99 and 84-100 having their confronting complemental teeth 97-105 and 98-106, respectively, separated at their minimum tolerance of disengagement. Neither head rest 13 nor knee rest 15-16 will move with the handle lever 124 in neutral position, but the brakes of both being in engagement these spring sections will hold and be locked against release under the weight of the patients body.

The important characteristic and effect of the instrumentalities described supra is that the brakes 74-81 and 75-86 will hold and lock the spring sections 13 and knee rest 15-16 until one or the other of the clutching elements 83-99 and 84-100 are substantially in complete engagement so that their respective spur gear drive 114- 115 or 114-116 will hold and maintain the spring section responsive thereto against accidental release while the braking elements 74-81 or 75-86 hold the other spring section against any possible movement. Thus, the spring sections 13 and 15-16 are always locked against accidental release and movement under the weight and influence of the patients body unless the gear train 114-115 or 114-116 is geared thereto for actuation. Should the electric motor 107 fail or in the event of power failure in the line to the motor 107, the reduction gearing built into the motor 107 will preclude the falling of the spring section then in operative connection with the gear train through the clutching elements 83-99 or 84-100 which is then in toothed engagement while the braking elements 74-81 and 75-86 of the alternate set locks the other spring section against release. The maximum clearance between the clutching teeth 97-105 and 98-106 is such that they just miss each other while their respective brake 74-81 or 75-86 is in full engagement to lock the spring section that otherwise would be free to move under the Weight of the patients body.

With the arrangement of parts above described, it will be apparent that a completely safe hospital bed spring section power actuator has been provided with dual drives that can be selectively rendered responsive to a single electric motor for adjusting the head rest and knee rest spring sections under the control of the attendants or the patient or both without any possible damage to the mechanism through inadvertant overrunning of the motor or failure of any part thereof in that automatic spring actuated brakes take hold and lock the parts unless the train of gears in the motor speed reducer and driving gear train are in operative engagement to actuate and adjust the spring section to insure locking of the parts in the event of any failure during such operation. The structure is simple, dependable in operation, and incapable of being damaged even though inexpert manipulation of the controls is practiced through inadvertence. The patient is safe at all times regardless of misuse, motor or-power failure, or inexpert control manipulation. Wear and accidental overrunning will not cause failure in the sense of damage to the working parts nor to the patientsafe support on the bed spring irrespective of the position of section adjustments at the time.

While I have illustrated and described a preferred embodiment of the invention, it must be understood that my invention is capable of considerable variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

I claim:

1. A power drive for hospital beds and the like having various sections for selective adjustable movement and locking upon command control comprising plural drive shafts, compound clutching and self-restoring braking means associated with each of said drive shafts in confronting relation, means for rotating said shafts, gear said plural shaft automatically effective when said clutching means are ineffective.

3. A power drive defined in claim 2 including singular means for simultaneously shifting complements of said clutching and braking means on each of said plural drive shafts so that one shaft at a time is operable while its braking counterpart is inoperable.

4. A power drive defined in claim 1 wherein spring means are provided to normally render said braking means automatically effective on each of said plural shafts when said clutching means are ineffective.

5. A power drive defined in claim 3 wherein the clutching and braking means are in axial alignment on each of said plural drive shafts for alternate engagement and disengagement depending upon the permissive operation of said self-restoring braking means.

6. A power drive defined in claim 4 wherein the clutching and braking means are in axial alignment on each of said plural drive shafts for alternate engagement and disengagement depending upon the permissive operation of said self-restoring braking means.

7. A power drive defined in claim 5 wherein manual remote shifting means are provided to render said clutching and braking means alternately effective and ineffective so that each shaft is selectively connected to said rotating means while the remaining shaft is held locked 'by said self-restoring braking means thereon. 8. A power drive defined in claim 6 wherein manual remote shifting means render said clutching means selectively effective while said spring means render said braking means in axial alignment therewith effective on unclutched shafts of said plural drive means.

9.-In a bed having an adjustable head rest, an adjustable knee rest, and means to adjust said head and knee rests, in combination with actuating means for said head and knee rest adjustable means, said actuating means including plural telescopic tube screw drive means for said knee rest and head rest adjustable means, a power drive for said plural drive means, a transmission interposed between said power drive and said adjustable means for said head rest and knee rest, said transmission comprising a train of gears interconnecting said plural drive means with said power drive, clutch means to selectively connect and disconnect said plural drive means to and from said train of gears, self-restoring bra-king means on said plural drive means for locking said head and knee rest adjustable means when their respective clutch means are inoperative, means for controlling the'operation of said power drive with each of said plural drive means, and means for selectively controlling the power operation of said plural drive means to selectively actuate or brake each of said head and knee rest adjustable means.

10. The structure defined in claim 9 wherein self-restoring braking means are rendered operative with spring means to normally maintain the braking complementsjin engagement.

11. The structure defined in claim 9 wherein said clutch and brake means are in axial alignment on each of said plural drive means, and complements of each of said clutch and brake means are integrally associated to longitudinally shift along said plural drive means to alternately connect and disconnect said clutch and brake means depending upon the permissive operation of said self-restoring braking means.

12. The structure defined in claim .11 including spring means for each of said brake means to render such selfrestoring and operative whenever said clutch means in axial alignment therewith is inoperative.

13. The structure defined in claim 12 including manual shifting means associated with said transmission to selectively shift the integrally associated complements of said clutch and brake mean on each of said plural drives to mechanically clutch and automatically render said brake means self-restoring when said clutch means are inoperative.

14. The structure defined in claim 12 including control means for shifting said integrally associated clutch and brake complements for rendering said head and knee rest adjustable means selectively operable by said power drive or automatically braked against movement.

15. The structure defined in claim 11 wherein the complemental clutch and brake means embody confronting toothed members relatively shiftable for engagement and disengagement.

16. The structure defined in claim 14 wherein the clutch and brake means include complemental confronting toothed members which are relatively displaceable for alternate cooperation to respectively connect and lock different head and knee rest adjustable means, whereby the attendant or bed patient can control the position of the head and knee rests within a wide range of adjustment.

10 17. The structure defined in claim 14 wherein said clutch and brake means have complemental elements of each on each integral shifter to alternately connect and disconnect said clutch and brake means.

References Cited by the Examiner UNITED STATES PATENTS 825,175 7/1906 Austin 192-4 1,525,965 2/1925 Thomas 192-18 2,403,095 7/1946 Lear 19214 X 2,475,997 7/ 1949 Smith 19218 2,505,221 4/1950 Tomlinson 1924 2,605,481 8/ 1952 Burkhart 569 2,620,489 12/1952 Holm 568 2,633,578 4/1953 Deves et a1 568 2,779,951 2/ 1957 Travis 569 2,913,300 11/1959 Darnell et .al 568 3,129,607 4/1964 Schaefer 200-47 3,191,196 6/1965 Holm 568 FRANK B. SHERRY, Primary Examiner.

C. A. NUNBERG, Assistant Examiner. 

1. A POWER DRIVE FOR HOSPITAL BEDS AND THE LIKE HAVING VARIOUS SECTIONS FOR SELECTIVE ADJUSTABLE MOVEMENT AND LOCKING UPON COMMAND CONTROL COMPRISING PLURAL DRIVE SHAFTS, COMPOUND CLUTCHING AND SELF-RESTORING BRAKING MEANS ASSOCIATED WITH EACH OF SAID DRIVE SHAFTS IN CONFRONTING RELATION, MEANS FOR ROTATING SAID SHAFTS, GEAR MEANS INTERPOSED BETWEEN SAID CLUTCHING MEANS AND ROTATING MEANS, AND MEANS FOR SELECTIVELY CONNECTING ONE OR THE OTHER OF SAID CLUTCHING MEANS TO ACTUATE ONE OF THE VARIOUS SECTIONS SELECTED FOR ADJUSTABLE MOVEMENT WHILE AUTOMATICALLY BRAKING THE REMAINING BED SECTIONS. 